Method of bleaching fatty oils, mineral oils, and the like



H". BOLLMANN April 15, 193p.

METHOD OF BLEACHING FATTY OILS, MINERAL OILS, AND THE LIKE Filed Dec.16, 1925 DRY FULLERS EAR-m an. HEATER INVENTOR.

OIL LEVEL sTmm-rfi 01L H EATER HEAT HEATING JACKET ATTORNEYS.

Patented Apr. is, 1930 PAT ENT OFFICE HERMANIN IBOLLMANN, OF HAMBURG,GERMANY IIMIIEII-IOD OF BLEACHING FATTY OILS, M INERAL OILS, AND THELIKE Application filed December 16, 1925, Serial No. 75,743, and in theNetherlands November 18, 1925.

which experiment has shown to be necessary I,

to the oil and to cause this mixture to react while stirring and heatinguntil the bleaching is effected. It has been proposed to make theprocess continuous by causing oil and fullers earth impregnated with oiltorpass through a suitable column in countercu'rrent or by conductingthem in the same direction through a pipe of suitable length providedwith an agitating device. 1

Experiments have now shown that the manner and proportions in which theoil and fullers earth are allowed to contact are of primary importancenot only with regard to the bleaching effectiveness of the fullers earthbut also with regard to the time required for the process.

The bleaching action depends on the high absorptive and adsorptivepowers of the fullers earth which has the property of retaining thecolouring constituents of the oil. If a comparatively large quantity offullers earth is brought into contact with a comparatively smallquantity of oil, the former immediately takes up the colouringconstituents. In addition, however, the fullers earth saturates itselfwith oil that has already been bleached, with the result that itsabsorptive powers towards the oil which is not yet bleached arediminished. Consequently a considerably larger quantity of'fullers earthand a longer period of action are necessary in the case when oil andfullers earth are not; mixed in the ratio requisite for the bleachingthan would be necessary if the mixture is made in the first place in thecorrect proportions.

First ewpemment It has been, for instance, found that soybean oil, mixedwith 12% of fullers earth and agitated while beingheated in a vessel,re-

quired about two hours before the bleaching was completed.

On the other hand, it has been found that if the oil is first warmed andthe fullers earth then added in small quantities and in a heated stateand brought into intimate contact with the oil or oil particles so thatthe addition of the fullers earth is spread over the entire period ofthe treatment and the fresh fullers earth has an opportunity of cominginto contact with unbleached oil, then under otherwise equalexperimental conditions it is possible to use 9% of fullers earth onlyand moreover to effect bleaching to the same degree as in the firstexperiment in less than half an hour.

The conclusion to be drawn from this is, therefore, that the bleachingmay be effected most quickly and effectively if oil and fullers earthare, at the start, intimately mixed in the F correct proportions.

Accordingly the method of this invention consists in causing fullersearth and oil under treatment to come into intimate contact in smallquantities at a time and in the requisite proportions for bleaching. Thefullers earth, preferably heated, say to about 100 0., is convenientlyforced into contact with the oil by means of a current of air underpressure, while the oil, also preferably heated, say to about 100 C., isconveniently sprayed into a chamber where the bleaching is to beeffected. Thus the finely divided hot fullers earth contacts with thespray of preheated oil.

\ To carry out the method on a large scale a closed vessel, providedwith a heating jacket and agitating device, is employed, the oilentering this from above and being distributed over the entire crosssection of the vessel while the fresh fullers earth is, at the sametime,

time the oil leaves the same. It is, however,

ible to use a smaller vessel and to finish OK the bleaching afterefiecting the mixing, in

another vessel, after which oil and fullers earth are separated in knownmanner, e. g. by filtration.

An apparatus for carrying out the method is illustrated diagrammaticallyand by way of example in the accompanying drawing.

The 011, previously warmed, is introduced through several nozzles 4 intothe closed yessel 1 provided with a heating jacket 2 and an 'tatindevice 3. The distribution of the o is e ected so that it takes placeover the entire cross section of the vessel 1. The fullers earth isconveyed by means of the conveyor screw 5 rotating in a pipe 14,provided with a heating jacket 17, into the pipe 6, the wall of which isprovided in its lower portion with openings. The pipe 6 is perforated inits lower portion and is open at the bottom,

7 and surrounded by the jacket 7. Air is blown into the jacket 7 bymeans of the pump 8 and passes through the openings in the pipe 6,thence out through the open lower end of pipe 6 into the receptacle 1.The pump 8 withdraws air from the vessel 1 in order to avoid contactingthe oil with excessive quantities of air. A gauze filter 16 preventsfullers earth entering the pump 8. The air entering vertical pipe 6 fromthe (perforations, mixes with the falling owdere fullers earth, and themixture wil be deflected by striking the upper flaring surface of thecone 9, to throw the same outwardly over practically the entire surfaceof the receptacle 1. This action is assisted by the fact that the cone 9is carried on a rotating rod 10. Much of the fullers earth beforestriking the body of the oil, will be struck by the sprays of hot oilfrom 4-4.

In the neighbourhood of the bottom of the vessel 1 an outlet pipe 11 issituated, which is connected with the ipe 12 which is closed at the topand is provi ed with agitating mechanism 15. The pi 12 has a number ofcocks 13 by means of which the contents of the vessel 1 ma be removed.The oil still carrying some in lers earth, drawn off from the cooks 13is first of all tested to determine whether the bleaching is completeand is then filtered or otherwise separated from the fullers earthcarried therein. The discharge flow is so regulated that the oil andfullers earth have been in contact for a suificient time to enable aneffective bleaching to take place.

I claim 1. A method of bleaching fatty oils, mineral oils and the likeby means of fullers earth, which consists in causing the fullers earthand oil to come into intimate contact both in small quantities at a timeboth the oil and fullers earth being in a finely subdivided state,whereb a minimum quantity of fullers earth su ces for bleaching.

, 2. A method of bleaching fatty oils,'mineral oils and the like bymeans of fullers earth, which consists in blowing fullers earth intocontact with the oil in the form of a spray, while fresh portions offullers earth and fresh quantities of unbleached oil are continuallycontacting with each other.

3. A method of bleaching fatty oils, mineral oils and the like by meansof fullers ers earth while in a heated 'state, until said earth hassufficiently removed the coloring matter from the oil.

5. In the bleaching of oil by fullers earth,-

the herein described step of directing a current of air carrying fullersearth against a spray of oil, to mix the said fullers earth and oil witheach other.

In testimony whereof I afiix 111 Signature.

HERMANN BOL MANN.

